You might have dead chips (marked as A) on your board that want go anywhere else then 0, ... and autotune ("a") will even be turn of on them and you might have bad chips which autotune will probably tune down to 0 clockspeed, but still autotune ("A") will be turned on (marked as B).

For dead chips there is no solution from software side that I know off. There might be some Hardware possibilities ... I don't know.

For bad chips there is!

First you need to turn of autotune "A" to "a" so that they wont be turned down to 0, because right know as long as they produce to many errors, they will be turned down until 0.

To start of set there clockspeed to 55 on the bad chip and let him run for 10-15 min. Check again. If he is performing better or not ... find a good rate between good and error. You might go down to 54 or 53 ... just check again, where the bad chip is performing at his max. potential ... at the end it might look like this one ...

* a bad one but still more then a stick

It might even be that bad chips get again running fine after running for hours (>24h) ... some users mentioned that bitfury chips have an integrated selfhealing mechanisme ... :-)

after chip #9 every coming chips go bad too, so I think I have to use the soldering jumpers - but I dont know how. Also it seems someone already used the soldering jumper on my chip #9 (if it is nr. 9). Can someone advice me here?

b) Affix each piece of VGA RAM Heatsink to the back of each BitFury chip on the H-Board. The RAM heatsinks come with thermal adhesives affixed.

c) Cut a 2 inch strip of DDR3 / DDR2 RAM heatskink for cooling the regulator area. Affix the heatsink to the back of board near the regulator with either thermally conductive glue or use some kind of thermal paste and small dabs of superglue / epoxy at the edges

d) Pencil mod the board until voltage reaches 0.8V. One of my boards is at 0.8V another at 0.84V. I would say 0.85V is the max after which either the regulator will shut down or the hash rate will drop dramatically.

e) Cool the boards with 120mm or bigger cooling fans.

f) Play around with best.cnf (I first changed of all the chip speeds to 54, and measured nonce rate after 10mins of hashing, then changed to 55 and again measured nonce rates. Compared the differences on a excel spreadsheet, and chose 54 or 55 depending on which produced higher hash rates for the chip.)

d) Pencil mod the board until voltage reaches 0.8V. One of my boards is at 0.8V another at 0.84V. I would say 0.85V is the max after which either the regulator will shut down or the hash rate will drop dramatically.

d) Pencil mod the board until voltage reaches 0.8V. One of my boards is at 0.8V another at 0.84V. I would say 0.85V is the max after which either the regulator will shut down or the hash rate will drop dramatically.

how many is it in ohm on resistor?

i usually donot measure ohms, I measure the output voltage of the regulator. But I think it should be between 1.05 to 1.08K on the mounted resistor.

d) Pencil mod the board until voltage reaches 0.8V. One of my boards is at 0.8V another at 0.84V. I would say 0.85V is the max after which either the regulator will shut down or the hash rate will drop dramatically.

how many is it in ohm on resistor?

i usually donot measure ohms, I measure the output voltage of the regulator. But I think it should be between 1.05 to 1.08K on the mounted resistor.

what about the area around the chip? you think this copper heatsinks are enough for dropping temp? ... how high is temp actualy? =) sorry my english soo bad^^

d) Pencil mod the board until voltage reaches 0.8V. One of my boards is at 0.8V another at 0.84V. I would say 0.85V is the max after which either the regulator will shut down or the hash rate will drop dramatically.

how many is it in ohm on resistor?

i usually donot measure ohms, I measure the output voltage of the regulator. But I think it should be between 1.05 to 1.08K on the mounted resistor.

b) Affix each piece of VGA RAM Heatsink to the back of each BitFury chip on the H-Board. The RAM heatsinks come with thermal adhesives affixed.

c) Cut a 2 inch strip of DDR3 / DDR2 RAM heatskink for cooling the regulator area. Affix the heatsink to the back of board near the regulator with either thermally conductive glue or use some kind of thermal paste and small dabs of superglue / epoxy at the edges

d) Pencil mod the board until voltage reaches 0.8V. One of my boards is at 0.8V another at 0.84V. I would say 0.85V is the max after which either the regulator will shut down or the hash rate will drop dramatically.

e) Cool the boards with 120mm or bigger cooling fans.

f) Play around with best.cnf (I first changed of all the chip speeds to 54, and measured nonce rate after 10mins of hashing, then changed to 55 and again measured nonce rates. Compared the differences on a excel spreadsheet, and chose 54 or 55 depending on which produced higher hash rates for the chip.)

Two quick questions on the goxxed info. 1) What points are you using exactly to measure the altered voltage? I am leery to probe around the board while powered up for fear of shorting something. 2) What exactly is reniceing and why is it important to reduce? This is the first time I have seen this term used in the bitfury threads.

Thanks very much and awesome work!

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